Add AVR SPI driver

git-svn-id: svn://svn.code.sf.net/p/chibios/svn/trunk@5892 35acf78f-673a-0410-8e92-d51de3d6d3f4
master
utzig 2013-06-26 17:59:59 +00:00
parent cb671fe992
commit 848d54b242
4 changed files with 635 additions and 1 deletions

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@ -108,3 +108,15 @@
* . * .
* @ingroup AVR_DRIVERS * @ingroup AVR_DRIVERS
*/ */
/**
* @defgroup AVR_SPI AVR SPI Support
* @details The AVR SPI driver uses the SPI peripheral (USART in SPI mode
* is not supported). It is an interrupt driven implementation.
*
* @section avr_spi Supported HW resources
* The spi driver can support the following hardware resource:
* - SPI.
* .
* @ingroup AVR_DRIVERS
*/

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@ -2,7 +2,8 @@
PLATFORMSRC = ${CHIBIOS}/os/hal/platforms/AVR/hal_lld.c \ PLATFORMSRC = ${CHIBIOS}/os/hal/platforms/AVR/hal_lld.c \
${CHIBIOS}/os/hal/platforms/AVR/pal_lld.c \ ${CHIBIOS}/os/hal/platforms/AVR/pal_lld.c \
${CHIBIOS}/os/hal/platforms/AVR/serial_lld.c \ ${CHIBIOS}/os/hal/platforms/AVR/serial_lld.c \
${CHIBIOS}/os/hal/platforms/AVR/i2c_lld.c ${CHIBIOS}/os/hal/platforms/AVR/i2c_lld.c \
${CHIBIOS}/os/hal/platforms/AVR/spi_lld.c
# Required include directories # Required include directories
PLATFORMINC = ${CHIBIOS}/os/hal/platforms/AVR PLATFORMINC = ${CHIBIOS}/os/hal/platforms/AVR

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/*
ChibiOS/RT - Copyright (C) 2006,2007,2008,2009,2010,
2011,2012,2013 Giovanni Di Sirio.
This file is part of ChibiOS/RT.
ChibiOS/RT is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 3 of the License, or
(at your option) any later version.
ChibiOS/RT is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
/**
* @file AVR/spi_lld.c
* @brief AVR SPI subsystem low level driver source.
*
* @addtogroup SPI
* @{
*/
#include "ch.h"
#include "hal.h"
#if HAL_USE_SPI || defined(__DOXYGEN__)
/*===========================================================================*/
/* Driver local definitions. */
/*===========================================================================*/
/*===========================================================================*/
/* Driver exported variables. */
/*===========================================================================*/
/**
* @brief SPI1 driver identifier.
*/
#if USE_AVR_SPI || defined(__DOXYGEN__)
SPIDriver SPID;
#endif
/*===========================================================================*/
/* Driver local variables and types. */
/*===========================================================================*/
/*===========================================================================*/
/* Driver local functions. */
/*===========================================================================*/
/*===========================================================================*/
/* Driver interrupt handlers. */
/*===========================================================================*/
#if USE_AVR_SPI || defined(__DOXYGEN__)
/**
* @brief SPI event interrupt handler.
*
* @notapi
*/
CH_IRQ_HANDLER(SPI_STC_vect) {
CH_IRQ_PROLOGUE();
SPIDriver *spip = &SPID;
/* spi_lld_exchange */
if (spip->rxbuf && spip->txbuf) {
spip->rxbuf[spip->rxidx++] = SPDR;
if (spip->rxidx == spip->rxbytes) {
_spi_isr_code(spip);
} else {
SPDR = spip->txbuf[spip->txidx++];
}
/* spi_lld_send */
} else if (spip->txbuf) {
if (spip->txidx < spip->txbytes) {
SPDR = spip->txbuf[spip->txidx++];
} else {
_spi_isr_code(spip);
}
/* spi_lld_receive */
} else if (spip->rxbuf) {
spip->rxbuf[spip->rxidx++] = SPDR;
if (spip->rxidx < spip->rxbytes) {
/* must keep clocking SCK */
SPDR = 0;
} else {
_spi_isr_code(spip);
}
/* spi_lld_ignore */
} else {
if (spip->txidx < spip->txbytes) {
SPDR = 0;
} else {
_spi_isr_code(spip);
}
}
CH_IRQ_EPILOGUE();
}
#endif /* USE_AVR_SPI */
/*===========================================================================*/
/* Driver exported functions. */
/*===========================================================================*/
/**
* @brief Low level SPI driver initialization.
*
* @notapi
*/
void spi_lld_init(void) {
#if USE_AVR_SPI
/* Driver initialization.*/
spiObjectInit(&SPID);
#endif /* USE_AVR_SPI */
}
/**
* @brief Configures and activates the SPI peripheral.
*
* @param[in] spip pointer to the @p SPIDriver object
*
* @notapi
*/
void spi_lld_start(SPIDriver *spip) {
uint8_t dummy;
/* Configures the peripheral.*/
if (spip->state == SPI_STOP) {
/* Enables the peripheral.*/
#if USE_AVR_SPI
if (&SPID == spip) {
/* enable SPI clock */
PRR0 &= ~(1 << PRSPI);
/* SPI interrupt enable, SPI enable, Master mode */
SPCR |= ((1 << SPE) | (1 << MSTR));
spip->config->ssport->dir |= (1 << spip->config->sspad);
/* XXX: For SPI to work as master, MOSI/SCK must be
* configured as outputs on your own code!
*/
switch (spip->config->bitorder) {
case SPI_LSB_FIRST:
SPCR |= (1 << DORD);
break;
case SPI_MSB_FIRST: /* fallthrough */
default:
SPCR &= ~(1 << DORD);
break;
}
SPCR &= ~((1 << CPOL) | (1 << CPHA));
switch (spip->config->mode) {
case SPI_MODE_1:
SPCR |= (1 << CPHA);
break;
case SPI_MODE_2:
SPCR |= (1 << CPOL);
break;
case SPI_MODE_3:
SPCR |= ((1 << CPOL) | (1 << CPHA));
break;
case SPI_MODE_0: /* fallthrough */
default: break;
}
SPCR &= ~((1 << SPR1) | (1 << SPR0));
SPSR &= ~(1 << SPI2X);
switch (spip->config->clockrate) {
case SPI_SCK_FOSC_2:
SPSR |= (1 << SPI2X);
break;
case SPI_SCK_FOSC_8:
SPSR |= (1 << SPI2X);
SPCR |= (1 << SPR0);
break;
case SPI_SCK_FOSC_16:
SPCR |= (1 << SPR0);
break;
case SPI_SCK_FOSC_32:
SPSR |= (1 << SPI2X);
SPCR |= (1 << SPR1);
break;
case SPI_SCK_FOSC_64:
SPCR |= (1 << SPR1);
break;
case SPI_SCK_FOSC_128:
SPCR |= ((1 << SPR1) | (1 << SPR0));
break;
case SPI_SCK_FOSC_4: /* fallthrough */
default: break;
}
/* dummy reads before enabling interrupt */
dummy = SPSR;
dummy = SPDR;
SPCR |= (1 << SPIE);
}
#endif /* USE_AVR_SPI */
}
}
/**
* @brief Deactivates the SPI peripheral.
*
* @param[in] spip pointer to the @p SPIDriver object
*
* @notapi
*/
void spi_lld_stop(SPIDriver *spip) {
if (spip->state == SPI_READY) {
/* Resets the peripheral.*/
/* Disables the peripheral.*/
#if USE_AVR_SPI
if (&SPID == spip) {
SPCR &= ((1 << SPIE) | (1 << SPE));
spip->config->ssport->dir &= ~(1 << spip->config->sspad);
}
#endif /* USE_AVR_SPI */
}
}
/**
* @brief Asserts the slave select signal and prepares for transfers.
*
* @param[in] spip pointer to the @p SPIDriver object
*
* @notapi
*/
void spi_lld_select(SPIDriver *spip) {
spip->config->ssport->out &= ~(1 << spip->config->sspad);
}
/**
* @brief Deasserts the slave select signal.
* @details The previously selected peripheral is unselected.
*
* @param[in] spip pointer to the @p SPIDriver object
*
* @notapi
*/
void spi_lld_unselect(SPIDriver *spip) {
spip->config->ssport->out |= (1 << spip->config->sspad);
}
/**
* @brief Ignores data on the SPI bus.
* @details This asynchronous function starts the transmission of a series of
* idle words on the SPI bus and ignores the received data.
* @post At the end of the operation the configured callback is invoked.
*
* @param[in] spip pointer to the @p SPIDriver object
* @param[in] n number of words to be ignored
*
* @notapi
*/
void spi_lld_ignore(SPIDriver *spip, size_t n) {
spip->rxbuf = spip->txbuf = NULL;
spip->txbytes = n;
spip->txidx = 0;
SPDR = 0;
}
/**
* @brief Exchanges data on the SPI bus.
* @details This asynchronous function starts a simultaneous transmit/receive
* operation.
* @post At the end of the operation the configured callback is invoked.
* @note The buffers are organized as uint8_t arrays for data sizes below or
* equal to 8 bits else it is organized as uint16_t arrays.
*
* @param[in] spip pointer to the @p SPIDriver object
* @param[in] n number of words to be exchanged
* @param[in] txbuf the pointer to the transmit buffer
* @param[out] rxbuf the pointer to the receive buffer
*
* @notapi
*/
void spi_lld_exchange(SPIDriver *spip, size_t n,
const void *txbuf, void *rxbuf) {
spip->rxbuf = rxbuf;
spip->txbuf = txbuf;
spip->txbytes = spip->rxbytes = n;
spip->txidx = spip->rxidx = 0;
SPDR = spip->txbuf[spip->txidx++];
}
/**
* @brief Sends data over the SPI bus.
* @details This asynchronous function starts a transmit operation.
* @post At the end of the operation the configured callback is invoked.
* @note The buffers are organized as uint8_t arrays for data sizes below or
* equal to 8 bits else it is organized as uint16_t arrays.
*
* @param[in] spip pointer to the @p SPIDriver object
* @param[in] n number of words to send
* @param[in] txbuf the pointer to the transmit buffer
*
* @notapi
*/
void spi_lld_send(SPIDriver *spip, size_t n, const void *txbuf) {
spip->rxbuf = NULL;
spip->txbuf = txbuf;
spip->txbytes = n;
spip->txidx = 0;
SPDR = spip->txbuf[spip->txidx++];
}
/**
* @brief Receives data from the SPI bus.
* @details This asynchronous function starts a receive operation.
* @post At the end of the operation the configured callback is invoked.
* @note The buffers are organized as uint8_t arrays for data sizes below or
* equal to 8 bits else it is organized as uint16_t arrays.
*
* @param[in] spip pointer to the @p SPIDriver object
* @param[in] n number of words to receive
* @param[out] rxbuf the pointer to the receive buffer
*
* @notapi
*/
void spi_lld_receive(SPIDriver *spip, size_t n, void *rxbuf) {
spip->txbuf = NULL;
spip->rxbuf = rxbuf;
spip->rxbytes = n;
spip->rxidx = 0;
/* Write dummy byte to start communication */
SPDR = 0;
}
/**
* @brief Exchanges one frame using a polled wait.
* @details This synchronous function exchanges one frame using a polled
* synchronization method. This function is useful when exchanging
* small amount of data on high speed channels, usually in this
* situation is much more efficient just wait for completion using
* polling than suspending the thread waiting for an interrupt.
*
* @param[in] spip pointer to the @p SPIDriver object
* @param[in] frame the data frame to send over the SPI bus
* @return The received data frame from the SPI bus.
*/
uint16_t spi_lld_polled_exchange(SPIDriver *spip, uint16_t frame) {
uint16_t spdr = 0;
uint8_t dummy;
/* disable interrupt */
SPCR &= ~(1 << SPIE);
SPDR = frame >> 8;
while (!(SPSR & (1 << SPIF))) ;
spdr = SPDR << 8;
SPDR = frame & 0xFF;
while (!(SPSR & (1 << SPIF))) ;
spdr |= SPDR;
dummy = SPSR;
dummy = SPDR;
SPCR |= (1 << SPIE);
return spdr;
}
#endif /* HAL_USE_SPI */
/** @} */

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/*
ChibiOS/RT - Copyright (C) 2006,2007,2008,2009,2010,
2011,2012,2013 Giovanni Di Sirio.
This file is part of ChibiOS/RT.
ChibiOS/RT is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 3 of the License, or
(at your option) any later version.
ChibiOS/RT is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
/**
* @file AVR/spi_lld.h
* @brief AVR SPI subsystem low level driver header.
*
* @addtogroup SPI
* @{
*/
#ifndef _SPI_LLD_H_
#define _SPI_LLD_H_
#if HAL_USE_SPI || defined(__DOXYGEN__)
/*===========================================================================*/
/* Driver constants. */
/*===========================================================================*/
/** @brief SPI Mode (Polarity/Phase) */
#define SPI_CPOL0_CPHA0 0
#define SPI_CPOL0_CPHA1 1
#define SPI_CPOL1_CPHA0 2
#define SPI_CPOL1_CPHA1 3
#define SPI_MODE_0 SPI_CPOL0_CPHA0
#define SPI_MODE_1 SPI_CPOL0_CPHA1
#define SPI_MODE_2 SPI_CPOL1_CPHA0
#define SPI_MODE_3 SPI_CPOL1_CPHA1
/** @brief Bit order */
#define SPI_LSB_FIRST 0
#define SPI_MSB_FIRST 1
/** @brief SPI clock rate FOSC/x */
#define SPI_SCK_FOSC_2 0
#define SPI_SCK_FOSC_4 1
#define SPI_SCK_FOSC_8 2
#define SPI_SCK_FOSC_16 3
#define SPI_SCK_FOSC_32 4
#define SPI_SCK_FOSC_64 5
#define SPI_SCK_FOSC_128 6
/*===========================================================================*/
/* Driver pre-compile time settings. */
/*===========================================================================*/
/**
* @name Configuration options
* @{
*/
/**
* @brief SPI driver enable switch.
* @details If set to @p TRUE the support for SPI1 is included.
*/
#if !defined(USE_AVR_SPI) || defined(__DOXYGEN__)
#define USE_AVR_SPI FALSE
#endif
/** @} */
/*===========================================================================*/
/* Derived constants and error checks. */
/*===========================================================================*/
/*===========================================================================*/
/* Driver data structures and types. */
/*===========================================================================*/
/**
* @brief Type of a structure representing an SPI driver.
*/
typedef struct SPIDriver SPIDriver;
/**
* @brief SPI notification callback type.
*
* @param[in] spip pointer to the @p SPIDriver object triggering the
* callback
*/
typedef void (*spicallback_t)(SPIDriver *spip);
/**
* @brief Driver configuration structure.
* @note Implementations may extend this structure to contain more,
* architecture dependent, fields.
*/
typedef struct {
/**
* @brief Port used of Slave Select
*/
ioportid_t ssport;
/**
* @brief Pad used of Slave Select
*/
uint8_t sspad;
/**
* @brief Polarity/Phase mode
*/
uint8_t mode;
/**
* @brief Use MSB/LSB first?
*/
uint8_t bitorder;
/**
* @brief Clock rate of the subsystem
*/
uint8_t clockrate;
/**
* @brief Operation complete callback.
*/
spicallback_t end_cb;
/* End of the mandatory fields.*/
} SPIConfig;
/**
* @brief Structure representing an SPI driver.
* @note Implementations may extend this structure to contain more,
* architecture dependent, fields.
*/
struct SPIDriver {
/**
* @brief Driver state.
*/
spistate_t state;
/**
* @brief Current configuration data.
*/
SPIConfig *config;
#if SPI_USE_WAIT || defined(__DOXYGEN__)
/**
* @brief Waiting thread.
*/
Thread *thread;
#endif /* SPI_USE_WAIT */
#if SPI_USE_MUTUAL_EXCLUSION || defined(__DOXYGEN__)
#if CH_USE_MUTEXES || defined(__DOXYGEN__)
/**
* @brief Mutex protecting the bus.
*/
Mutex mutex;
#elif CH_USE_SEMAPHORES
Semaphore semaphore;
#endif
#endif /* SPI_USE_MUTUAL_EXCLUSION */
#if defined(SPI_DRIVER_EXT_FIELDS)
SPI_DRIVER_EXT_FIELDS
#endif
/**
* @brief Pointer to the buffer with data to send.
*/
const uint8_t *txbuf;
/**
* @brief Number of bytes of data to send.
*/
size_t txbytes;
/**
* @brief Current index in buffer when sending data.
*/
size_t txidx;
/**
* @brief Pointer to the buffer to put received data.
*/
uint8_t *rxbuf;
/**
* @brief Number of bytes of data to receive.
*/
size_t rxbytes;
/**
* @brief Current index in buffer when receiving data.
*/
size_t rxidx;
};
/*===========================================================================*/
/* Driver macros. */
/*===========================================================================*/
/*===========================================================================*/
/* External declarations. */
/*===========================================================================*/
#if USE_AVR_SPI && !defined(__DOXYGEN__)
extern SPIDriver SPID;
#endif
#ifdef __cplusplus
extern "C" {
#endif
void spi_lld_init(void);
void spi_lld_start(SPIDriver *spip);
void spi_lld_stop(SPIDriver *spip);
void spi_lld_select(SPIDriver *spip);
void spi_lld_unselect(SPIDriver *spip);
void spi_lld_ignore(SPIDriver *spip, size_t n);
void spi_lld_exchange(SPIDriver *spip, size_t n,
const void *txbuf, void *rxbuf);
void spi_lld_send(SPIDriver *spip, size_t n, const void *txbuf);
void spi_lld_receive(SPIDriver *spip, size_t n, void *rxbuf);
uint16_t spi_lld_polled_exchange(SPIDriver *spip, uint16_t frame);
#ifdef __cplusplus
}
#endif
#endif /* HAL_USE_SPI */
#endif /* _SPI_LLD_H_ */
/** @} */